553 research outputs found
Real-time Substrate Transport Control for Stable and Efficient Thin-film-based Roll-to-roll (R2R) Micro-nanomanufacturing
The commercialization of electronic devices requires the high efficiency and stable mirco-nanomanufacturing processes that allow frequent design upgrades. R2R Nano is a gateway to science and engineering research that aims to impact the widespread adoption of R2R technologies for low-cost, high-volume production of high technology products on flexible substrates. However, there are lots of the mechanical and chemical factors influencing the system performance when fabricating nano-scale structures. Thus, feedback control system is increasingly playing a great role in improving the R2R performance.
The aim of the project is to design a feedback control system for enhancing the performance of the R2R system by harmonizing between the moving speed of substrate, film surface energy and substrate’s tension. In this project, a roll of thin-film with several microns thickness is used as substrate which allows lower process cost and surface quality but also make the substrate transport more challenging than working with much thicker substrate. The control system design mainly consist several subcomponents such as the thin film substrate tension control, nano-patterned liquid dispenser and real-time feedback controller (LabVIEW programming). As a result, the control scheme will allow fabricating uniform nanostructures over a large area at a desired throughput.
Based on the improved R2R mechanism, multi-processing can be developed such as imprinting, LWD (laser induced direct-writing) and coating. In the experiment, copper nanoparticles will be used as the substrate to test the performance of the system
Impact of feature proportion on matching performance of multi-biometric systems
Biometrics as a tool for information security has been used in various applications. Feature-level fusion is widely used in the design of multi-biometric systems due to its advantages in increasing recognition accuracy and security. However, most existing multi-biometric systems that use feature-level fusion assign each biometric trait an equal proportion when combining features from multiple sources. For example, multi-biometric systems with two biometric traits commonly adopt a 50–50 feature proportion setting, which means that fused feature data contains half elements from each biometric modality. In this paper, we investigate the impact of feature proportion on the matching performance of multi-biometric systems. By using a fingerprint and face based multi-biometric system that applies feature-level fusion, we employ a random projection based transformation and a proportion weight factor. By adjusting this weight factor, we show that allocating unequal proportions to features from different biometric traits yields different matching performance. Our experimental results indicate that optimal performance, achieved with unequal feature proportions, could be better than the performance obtained with the commonly used 50–50 feature proportion. Therefore, the impact of feature proportion, which has been ignored by most existing work, should be taken into account and more study is required as to how to make feature proportion allocation benefit the performance of multi-biometric systems
Railway Container Station Reselection Approach and Application: Based on Entropy-Cloud Model
Reasonable railway container freight stations layout means higher transportation efficiency and less transportation cost. To obtain more objective and accurate reselection results, a new entropy-cloud approach is formulated to solve the problem. The approach comprises three phases: Entropy Method is used to obtain the weight of each subcriterion during Phase 1, then cloud model is designed to form the evaluation cloud for each subcriterion during Phase 2, and finally during Phase 3 we use the weight during Phase 1 to multiply the initial evaluation cloud during Phase 2. MATLAB is applied to determine the evaluation figures and help us to make the final alternative decision. To test our approach, the railway container stations in Wuhan Railway Bureau were selected for our case study. The final evaluation result indicates only Xiangyang Station should be renovated and developed as a Special Transaction Station, five other stations should be kept and developed as Ordinary Stations, and the remaining 16 stations should be closed. Furthermore, the results show that, before the site reselection process, the average distance between two railway container stations was only 74.7 km but has improved to 182.6 km after using the approach formulated in this paper
Biometrics based privacy-preserving authentication and mobile template protection
Smart mobile devices are playing a more and more important role in our daily life. Cancelable biometrics is a promising mechanism to provide authentication to mobile devices and protect biometric templates by applying a noninvertible transformation to raw biometric data. However, the negative effect of nonlinear distortion will usually degrade the matching performance significantly, which is a nontrivial factor when designing a cancelable template. Moreover, the attacks via record multiplicity (ARM) present a threat to the existing cancelable biometrics, which is still a challenging open issue. To address these problems, in this paper, we propose a new cancelable fingerprint template which can not only mitigate the negative effect of nonlinear distortion by combining multiple feature sets, but also defeat the ARM attack through a proposed feature decorrelation algorithm. Our work is a new contribution to the design of cancelable biometrics with a concrete method against the ARM attack. Experimental results on public databases and security analysis show the validity of the proposed cancelable template
A review of multi-factor authentication in the internet of healthcare things
Objective: This review paper aims to evaluate existing solutions in healthcare authentication and provides an insight into the technologies incorporated in Internet of Healthcare Things (IoHT) and multi-factor authentication (MFA) applications for next-generation authentication practices. Our review has two objectives: (a) Review MFA based on the challenges, impact and solutions discussed in the literature; and (b) define the security requirements of the IoHT as an approach to adapting MFA solutions in a healthcare context. Methods: To review the existing literature, we indexed articles from the IEEE Xplore, ACM Digital Library, ScienceDirect, and SpringerLink databases. The search was refined to combinations of ‘authentication’, ‘multi-factor authentication’, ‘Internet of Things authentication’, and ‘medical authentication’ to ensure that the retrieved journal articles and conference papers were relevant to healthcare and Internet of Things-oriented authentication research. Results: The concepts of MFA can be applied to healthcare where security can often be overlooked. The security requirements identified result in stronger methodologies of authentication such as hardware solutions in combination with biometric data to enhance MFA approaches. We identify the key vulnerabilities of weaker approaches to security such as password use against various cyber threats. Cyber threats and MFA solutions are categorised in this paper to facilitate readers’ understanding of them in healthcare domains. Conclusions: We contribute to an understanding of up-to-date MFA approaches and how they can be improved for use in the IoHT. This is achieved by discussing the challenges, benefits, and limitations of current methodologies and recommendations to improve access to eHealth resources through additional layers of security
Iterative Poisson Surface Reconstruction (iPSR) for Unoriented Points
Poisson surface reconstruction (PSR) remains a popular technique for
reconstructing watertight surfaces from 3D point samples thanks to its
efficiency, simplicity, and robustness. Yet, the existing PSR method and
subsequent variants work only for oriented points. This paper intends to
validate that an improved PSR, called iPSR, can completely eliminate the
requirement of point normals and proceed in an iterative manner. In each
iteration, iPSR takes as input point samples with normals directly computed
from the surface obtained in the preceding iteration, and then generates a new
surface with better quality. Extensive quantitative evaluation confirms that
the new iPSR algorithm converges in 5-30 iterations even with randomly
initialized normals. If initialized with a simple visibility based heuristic,
iPSR can further reduce the number of iterations. We conduct comprehensive
comparisons with PSR and other powerful implicit-function based methods.
Finally, we confirm iPSR's effectiveness and scalability on the AIM@SHAPE
dataset and challenging (indoor and outdoor) scenes. Code and data for this
paper are at https://github.com/houfei0801/ipsr
Security and accuracy of fingerprint-based biometrics: A review
Biometric systems are increasingly replacing traditional password- and token-based authentication systems. Security and recognition accuracy are the two most important aspects to consider in designing a biometric system. In this paper, a comprehensive review is presented to shed light on the latest developments in the study of fingerprint-based biometrics covering these two aspects with a view to improving system security and recognition accuracy. Based on a thorough analysis and discussion, limitations of existing research work are outlined and suggestions for future work are provided. It is shown in the paper that researchers continue to face challenges in tackling the two most critical attacks to biometric systems, namely, attacks to the user interface and template databases. How to design proper countermeasures to thwart these attacks, thereby providing strong security and yet at the same time maintaining high recognition accuracy, is a hot research topic currently, as well as in the foreseeable future. Moreover, recognition accuracy under non-ideal conditions is more likely to be unsatisfactory and thus needs particular attention in biometric system design. Related challenges and current research trends are also outlined in this paper
Devices for surface working by plane means of vibration rolling
The analysis of manufacturing and technology accessories for regular micro-relief forming at
flat surfaces by vibration rolling is given. The new design of apparatus providing an equal
vibration roling forces at all vibration rolling devices is proposed
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